SMEFT effects on spin correlations and entanglement at NLO QCD in diboson production at hadron colliders

We perform for the first time a full study of spin correlations in inclusive production of WZ boson pairs at the LHC with leptonic decays in the presence of next-to-leading-order QCD corrections and of effects from a dimension-six operator in the Standard-Model effective field theory (SMEFT) modifying the electroweak triple-gauge coupling. We carry out the complete quantum-state tomography of the diboson system and relate its results to common purity and spin-entanglement markers, highlighting the sizeable impact of both QCD corrections and SMEFT insertions. Additionally, we show how a naïve truncation at dimension six in the SMEFT expansion of the spin-density matrix can lead to a cumbersome spin interpretation of the quantum-tomography results.